This invention relates generally to high power metal vapor lasers, and, more particularly to a high power lead vapor laser which incorporates therein a recirculating wick structure.
During the past decade the metal vapor laser has become an important source of high power, high efficiency laser radiation in the visible and near-visible portions of the spectrum. Numerous applications for a laser source in the blue-green region of the spectrum has focused attention on the copper vapor laser. Unfortunately, this concentration on the copper vapor laser has no doubt been responsible, at least in part, for the first that the lead vapor laser has lagged behind that of the copper laser.
However, there exists some applications for which the principal lead vapor laser wavelength at 722.9 nm in the near IR is more suitable. For example, this type of laser is currently being developed and packaged for use as an illuminator for a low light level TV camera. It is therefore becoming more and more beneficial to increase the output power from the lead vapor laser.
One major effort to increase the output power from the lead vapor laser involves exciting the laser with considerably higher input power than typically used in the past. Under high input power conditions, however, it has been found that the ceramic discharge tube utilized within the laser invariably fractured at the high voltage end of the laser after limited operating time. All evidence indicates that the breakage of the ceramic discharge tube is due to stresses induced in the ceramic tube by the high electric field strengths which occur during high input power conditions. In particular, this problem occurs more readily in lead vapor lasers which incorporate electrodes or recirculating wick structures within the walls of the ceramic discharge tube at the high voltage end.
It would therefore be extremely desirable if a high power metal vapor laser and, in particular, the lead vapor laser could be designed which overcomes the problems of discharge tube breakage after short term operation of the laser.